1. Field of the Invention
The present invention relates to an electrophotosensitive member for use in the electrophotography process.
2. Description of the Prior Arts
An electrophotosensitive member comprising a support and a photosensitive layer formed on the surface of the support has been known as the conventional electrophotosensitive member for use in the electrophotography process.
In general, the durability and the anti-abrasion property of the surface are required for an electrophotosensitive member for use in the electrophotograpy process to always maintain a favorable electrophotography characteristic even during quite a long period of the repetitive operation.
An electrophotosensitive member having an overcoat layer formed on the photosensitive layer has been known. The purpose of the overcoat layer is for improving the durability and the anti-abrasion property of the photosensitive layer's surface. For instance, the Japanese Published Unexamined Patent Application No. 59454/1983 discloses an electrophotosensitive member having an overcoat layer which comprises inorganic materials, such as silicon oxide (SiO), magnesium oxide (MgO) and the like, coating the surface of the photosensitive layer.
The overcoat layer is effective in protecting the photosensitive layer, but the smoothness of the surface of the overcoat layer is so high that the friction force between the overcoat layer and a cleaning device, which contacts and cleans the overcoat layer, increases, because the contacting area between the overcoat layer and the cleaning device is large. As a result, the durability of the overcoat layer decreases.
On the other hand, U.S. Pat. No. 3,992,091 discloses a technique to form a rough surface on the support to reduce the friction coefficient between the surface of the electrophotosensitive member and the cleaning device which contacts and cleans the surface of the electrophotosensitive member. It forms the rough surface by etching the surface of the support chemically or by a mechanical process before coating and forming the photosensitive layer on the support. However, the process for roughing the surface disclosed in the technique is so complicated that it is disadvantageous from the cost point of view. Further, the above technique is hard to control the roughness of the rough surface because the surface of the photosensitive member is roughed indirectly: first the surface of the support is roughed and then the photosensitive member is formed on the roughed surface of the support.